The present invention generally relates to methods and machines for cutting products. The invention particularly relates to machines equipped with an impeller adapted to transport products to at least one knife suitable for cutting the product, wherein the impeller is capable of transporting and orienting products that are relatively small, for example, the size of a small potato and smaller.
Various types of equipment are known for slicing, shredding and granulating food products, such as vegetable, fruit, dairy, and meat products. A widely used line of machines for this purpose is commercially available from Urschel Laboratories, Inc., under the name Urschel Model CC®, an embodiment of which is represented in FIG. 1. The Model CC® machine line provides versions of centrifugal-type slicers capable of producing uniform slices, strip cuts, shreds and granulations of a wide variety of products at high production capacities. When used to produce potato slices for potato chips, the Model CC® line of machines can make use of substantially round potatoes to produce the desired circular chip shape with a minimum amount of scrap.
The Model CC® machine 10 schematically represented in FIG. 1 includes a cutting head 12 mounted on a support ring 15 above a gear box 16. A housing 18 contains a shaft coupled to the gear box 16 that rotates an impeller 14 within the cutting head 12. Products are delivered to the cutting head 12 and impeller 14 through a feed hopper 11 located above the cutting head 12. In operation, the impeller 14 is coaxially mounted within the cutting head 12, which is generally annular-shaped with cutting knives (not shown) mounted at its perimeter. The impeller 14 rotates within the cutting head 12, while the latter remains stationary. The hopper 11 delivers products to the middle of the impeller 14, and centrifugal force causes the products to move outward into engagement with the knives of the cutting head 12. Further descriptions pertaining to the construction and operation of Model CC® machines, including improved embodiments thereof, are contained in U.S. Pat. Nos. 5,694,824 and 6,968,765, the entire contents of which are incorporated herein by reference.
FIG. 2 is a perspective view of a cutting head 12 and FIGS. 3 and 4 are perspective and cross-sectional views, respectively, of an impeller 14 of types that can be used in the Model CC® machine of FIG. 1. Referring to FIG. 2, each knife 13 of the cutting head 12 projects radially inward toward the interior of the cutting head 12, generally in a direction opposite the rotation of the impeller 14 within the cutting head 12, and defines a cutting edge at its radially innermost extremity. As represented in FIGS. 3 and 4, the impeller 14 comprises generally radially-oriented paddles 28 disposed between a base 30 and an upper ring 32, the latter being omitted in FIG. 4 to reveal the interior of the impeller 14 and orientations of the paddles 28. A frustoconical-shaped flange 34 extends in a generally axial direction from the ring 32 to define an opening 36 through which food products enter the impeller 14. The paddles 28 have faces 38 that engage and direct the products (e.g., potatoes) 39 radially outward towards and against the knives 13 of the cutting head 12 as the impeller 14 rotates. The cutting head 12 shown in FIG. 2 comprises a lower support ring 18, an upper support ring 20, and circumferentially-spaced support segments (shoes) 22. The knives 13 of the cutting head 12 are individually secured with clamping assemblies 26 to the shoes 22. Each clamping assembly 26 includes a knife holder 26A mounted to the radially inward-facing side of a shoe 22, and a clamp 26B mounted on the radially outward-facing side of a shoe 22 to secure the knife 13 to the knife holder 26A. The shoes 22 are represented as being secured with bolts 25 to the support rings 18 and 20. The shoes 22 are equipped with coaxial pivot pins (not shown) that engage holes in the support rings 18 and 20. By pivoting on its pins, the orientation of a shoe 22 can be adjusted to alter the radial location of the cutting edge of its knife 13 with respect to the axis of the cutting head 12, thereby controlling the thickness of the sliced product. As an example, adjustment can be achieved with an adjusting screw and/or pin 24 located circumferentially behind the pivot pins. FIG. 2 further shows optional gate insert strips 23 mounted to each shoe 22, which the product crosses prior to encountering the knife 13 mounted to the succeeding shoe 22.
The knives 13 shown in FIG. 2 are depicted as having straight cutting edges for producing flat slices, though other shapes are also used to produce sliced, strip-cut, shredded and granulated products. For example, the knives 13 can have cutting edges that define a periodic pattern of peaks and valleys when viewed edgewise. The periodic pattern can be characterized by sharp peaks and valleys, or a more corrugated or sinusoidal shape characterized by more rounded peaks and valleys when viewed edgewise. If the peaks and valleys of each knife 13 are aligned with those of the preceding knife 13, slices are produced in which each peak on one surface of a slice corresponds to a valley on the opposite surface of the slice, such that the slices are substantially uniform in thickness but have a cross-sectional shape that is characterized by sharp peaks and valleys (“V-slices”) or a more corrugated or sinusoidal shape (crinkle slices), collectively referred to herein as periodic shapes. Alternatively, shredded product can be produced if each peak of each knife 13 is aligned with a valley of the preceding knife 13, and waffle/lattice-cut product can be produced by intentionally making off-axis alignment cuts with a periodic-shaped knife, for example, by crosscutting a product at two different angles, typically ninety degrees apart. In addition, strip-cut and granulated products can be produced with the use of additional knives and/or cutting wheels located downstream of the knives 13. Whether a sliced, strip-cut, shredded, granulated, or waffle-cut product is desired will depend on the intended use of the product.
Equipment currently available for cutting product, such as those represented in FIGS. 1-4, are well suited for producing slices of a wide variety of food products. Even so, further improvements and versatility are desirable, particularly for producing slices, strip cuts, shreds and granulations from a wider variety of products at high production capacities. For example, under certain conditions it is desirable to process food products that are smaller than potatoes of sizes commonly used to produce potato chips, for example, food products having diameters of less than two to three inches. Particular but nonlimiting examples include food products such as almonds, coffee beans, strawberries, mushrooms, etc. For smaller products such as these, the products tend to encounter only a limited portion of each knife 13 at the lower end of the cutting head 12 (as viewed in FIG. 2). It may also be desirable for the impeller 14 to deliver smaller elongate products (for example, almonds, coffee beans) so that their major dimension has a particular orientation to the cutting head 12, for example, so that the major axis of each product is oriented to be functionally tangent to the outer diameter of the impeller 14, so that a majority of the cuts through the products are lengthwise and nearly parallel to their major axes.